US3192361A

US3192361A - Electric heater assembly

Info

Publication number: US3192361A
Application number: US215645A
Authority: US
Inventors: Richard L Post; Thomas A Oravetz
Original assignee: Edwin L Wiegand Co
Current assignee: Edwin L Wiegand Co
Priority date: 1962-08-08
Filing date: 1962-08-08
Publication date: 1965-06-29
Anticipated expiration: 1982-06-29

Description

June 29, 1965 R. L. POST ETAL 3,192,361

ELECTRIC HEATER ASSEMBLY 2 Sheets-Sheet 1 Filed Aug. 8, 1962 v T WLMM A O D; w

RT am 2 Sheets-Sheet 2 wi TuomAs AOQAVETZ ATTORNE/S June 29, 1965 Filed Aug. 8, 1962 VIIQAZ R z \W United States Patent 3,192,361 ELECTRIC HEATER ASSEMBLY Richard L. Post, Glenshaw, and Thomas A. Oravetz,

Level Green, Pa., assignors to Edwin L..Wiegand Company, Pittsburgh, Pa.

Filed Aug. 8, 1962, Ser. No. 215,645 8 Claims. (Cl. 219-458) The present invention relates to electric heater assemblies, more particularly to assemblies adapted for use in ranges, hot plates and the like, an dthe princi al object of the invention is to provide new and improved assemblies of the character described.

Although many prior-art heater assemblies of the surface, or range unit, type utilizing a tubular sheathed electric resistance heating element have been satisfactory in most respects, a common disability has been the high cost of the assembly which limited its use inlow price structures. One of the. primary objects of the present invention, therefore, is. the provision of an assembly incorporating a tubular sheathed electric resistance heating element which can be manufactured and sold at a sufficiently low price to justify its use in even low price structures; This and other advantages will readily become apparent from a study of the following description and from the drawings appended hereto.

In the drawings accompanying this specification and forming a part of this application there is shown, for purpose of illustration, an embodiment which the invention may assume, and in these drawings:

FIGURE 1 is a top plan view of an electric heater assembly embodying the present invention,

FIGURE 2 is a sectional view generally corresponding to the line 2-2 of FIGUREv 1',

FIGURE 3 is an exploded perspective view of certain details, and

FIGURE 4 is an enlarged, broken sectional view taken through the details seen in FIGURE 3 and generally corresponding to the line 4-4 but showing the details in assembled relation.

With reference to FIGURES 1 and 2, the present heater assembly utilizes the usual elongated, tubular sheathed electric resistance heating element whose intermediate, heat-generating portion 11 provides a plurality of convolutions forming a generally flat, centrally apertured, circular heating surface which is adapted to underlie and support a vessel (not shown) to be heated. Such convolutions are preferably flattened at the top (see FIGURE 2) to improve heat-contact with the bottom of the vessel to be heated. The terminal ends 12 of the heating element are disposed in side-by-side relation beneath the heating surface of the intermediate, heat-generating element portion 11 and extend beyond such heating surface for connection to a source of electrical energy.

Electrically connected to the free ends of respective element terminal ends 12 are insulated, flexible lead wires 13. Protecting each of the connections aforesaid is a molded body 14 of heat-resistant rubber or the like which extends between and is bonded to a respective element terminal end and the insulated covering of its attached lead wire. This construction completely seals the interior of the element against moisture or other foreign material, adequately protects the electrical connections against grounds or shorts, and eliminates the usual expensive terminal block.

In common with prior-art, range-type or surface heater assemblies, the assembly herein disclosed is adapted to be supported by an .apertured panel 15 which, in the present embodiment, may be considered as the top panel of a range or as the corresponding part of a hot plate or the like. As herein disclosed, a ring-like member 3,192,361 Patented June 29, 1965 16 having an upper, radially outwardly extending flange portion 17, a lower, radially inwardly extending flange portion 18, and an intermediate, tubular portion 19, is supported by the panel 15 with the tubular portion 19 disposed within the panel aperture and with the flange portion 17 resting upon the upper surface of the panel. Supported by the member 16 is the usual removable reflector, or drip pan, 20 having a radially outwardly extending flange 21 which rests upon the flange 18 of the member 16. Pan 20 is notched out at 22 to pass the element terminal ends 12.

Turning now to the means for supporting the element 10 Within the ring member 16, a supporting member 23, frequently known as a spider, underlies the heatgenerating portion of the element and rests upon the pan flange 21. Spider 23 provides three structurally integrated

legs

24, 25 and 26 (see FIGURE 1) arranged in spoke-like relation beneath the heat-generating portion of the element. The spider legs are herein shown formed of heat-resistant strip material, such as metal, positioned on edge for maximum strength in a vertical direction with the outermost leg ends resting upon the pan flange 21 and abutting the tubular ring portion 19.

As best seen in FIGURE 3, spider 23 is formed of two sheet metal pieces each having rectilinear portions 27 and 28 in angular relation joined by an arcuate portion 29. Rectilinear portions 27 are adapted to be disposed in face-to-face relation as shown and may be structurally integrally united by means of rivets 30. Port-ions 27, of course, combine to form the spider leg 24 while portions 28 form

respective spider legs

25, 26. Arcuate spider portions 29 together form approximately a half circle which is generally concentric with the central aperture of the element heating surface when the element and the spider are in superposed relation.

In the present embodiment, the heating element 10 and the spider 23 are adapted to be secured together and for this purpose, any convenient means may be employed. At the present time and as best seen in FIGURE 2, metal loops 31 are welded to the underside of certain element convolutions to closely receive the spider leg 24. For preventing unintentional disassembly of the spider and the element, the spider leg 24 is notched at 32 (see also FIGURE 3) to provide shoulders between which the loops are confined.

While the structure thus far described provides a complete, workable assembly, it is common practise to position a medallion 33 or like body within the central aperture of the element heating surface in order to impart a more finished appearance to the assembly. As best seen in FIGURES 3 and 4, medallion 33 preferably comprises a shallow, inverted sheet-metal cup whose annular wall 34 is of stepped diameter to provide an upwardly facing annular shoulder 35.

For securing the medallion to the spider, the arcuate portions 29 of the latter are lanced out at 36 to provide circumferentially spaced-apart tongues 37. With particular reference to FIGURE 4, the lower portion of each tongue 37 provides a radially inwardly projecting ledge upon which the lower margin of the medallion wall 34 rests while the upper portion of each tongue is spaced radially inwardly of its arcuate spider portion to closely receive the medallion wall. With the medallion thus positioned, each tongue 37 may be forced radially outwardly to gripping relation with the medallion to thus retain it assembled with the spider.

Since the spider tongues 37 are rather widely spaced, there might be tendency for the medallion to rock and eventually work itself loose. To prevent this, the arcuate portion 29 of each spider part is provided with radial inward projections 38 intermediate the spider tongues.

As seen in FIGURE 4, such projections may conveniently be formed by punching small portions of the spider radially inwardly an amount only sufficient to form projecbions but not sutlicient to punch the portions completely out.

Still referring to FIGURE 4, the lowermost projections 38 are positioned to engage beneath the lower edge of the medallion wall 34 while the uppermost projections 38 engage the upwardly facing, medallion wall shoulder 35 thus effectively preventing tilting of the medallion about the mounting tongues 37.

While a shallow, inverted cup-shaped medallion has been shown and described, it is to be understood that the invention contemplates the use of medallions of different shapes or the use of thermal sensing units or the like in place of medallions.

In view of the foregoing, it will be apparent to those skilled in the art that we have accomplished at least the principal object of our invention and it will also be apparent to those skilled in the art that the embodiment herein described may be variously changed and modified, without departing from the spirit of the invention, and that the invention is capable of uses and has advantages not herein specifically described; hence it will be appreciated that the herein disclosed embodiment is illustrative only, and that our invention is not limited thereto.

We claim:

1. A heater assembly comprising a sheathed electric resistance heating element having a heat-generating portion providing an apertured, generally plane heating surface for underlying and supporting a vessel to be heated, a support member underlying and supporting the heatgenerating portion of said element and partially margining the element heating surface aperture, means carried by that part of said support member which margins said element heating surface aperture and comprising a generally vertically disposed tongue having a lower portion affixed to said support member margining part and an upper, free end portion spaced radially inwardly of said support member margining part, and a body aligned with the element heating surface aperture and having a portion initerposed between said support member margining part and the free end portion of said tongue.

2. The construction of claim 1 wherein said body portion rests upon the lower portion of said tongue adjacent its juncture with said support member margining part.

3. The construction of claim 1 wherein said body portion is gripped between said support member margining part and the free end portion of said tongue.

4. The construction of claim 1 wherein said support member margining part provides a pair of radially inwardly extending projections which respectively engage upper and lower body portions to prevent tilting of said body relative to said support member.

5. The construction of claim 4 wherein said body portion is a sheet metal annulus, wherein the sheet metal annular body portion provides an upwardly facing annular flange, and wherein one of said projections engages the lower edge of said body portion and the other engages said annular flange.

6. The construction of claim 1 wherein said tongue is integral with said support member margining part and is formed by lancing said tongue therefrom.

7. The construction of claim 6 wherein said-support member provides a pair of circumferentially spaced tongues in generally opposed relation with each other.

8. The construction of claim 7 wherein said body portion is a sheet metal annulus, wherein said support member margining part provides a pair of radially inwardly extending projections intermediate said tongues, and wherein said projections respectively engage upper and lower body annular portions to prevent tilting of said body relative to said support member.

RICHARD M. WOOD, Primary Examiner.

Claims

1. A HEATER ASSEMBLY COMPRISING A SHEATHED ELECTRIC RESISTANCE HEATING ELEMENT HAVING A HEAT-GENERATING PORTION PROVIDING AN APERTURED, GENERALLY PLANE HEATING SURFACE FOR UNDERLYING AND SUPPORTING A VESSEL TO BE HEATED, A SUPPORT MEMBER UNDERLYING AND SUPPORTING THE HEATGENERATING PORTION OF SAID ELEMENT AND PARTIALLY MARGINING THE ELEMENT HEATING SURFACE APERTURE, MEANS CARRIED BY THAT PART OF SAID SUPPORT MEMBER WHICH MARGINS SAID ELEMENT HEATING SURFACE APERTURE AND COMPRISING A GENERALLY VERTICALY DISPOSED TONGUE HAVING A LOWER PORTION AFFIXED TO SAID SUPPORT MEMBER MARGINING PART AND AN UPPER, FREE END PORTION SPACED RADIALLY OF SAID SUPPORT MEMBER MARGINING PART, AND A BODY ALIGNED WITH THE ELEMENT HEATING SURFACE APERTURE AND HAVING A PORTION INTERPOSED BETWEEN SAID SUPPORT MEMBER MARGINING PART AND THE FREE END PORTION OF SAID TONGUE.